Dynamo-electric machine.



F. R. KUNKEL. DYNAMo ELECTRIC MACHINE. APPLIGATION FILED DEC.29,1909.

1,123,319, Patented tmn.5,1915.

mfr q mi! mumlllll,

. other small machines of this class.

UNITED sTATEs PATENT oEErcE.

FRED R.,KUNK EL, 0F EDGEWUOD PARK, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY. A CORPORATION OF PENNSYLVANIA.'

Specification of Letters Patent.

DYNAMD-ELECTRIC MACHINE.

Patented Jan. 5, 1915.

Application led December 29, 1909. SerialiNo. 535,401.

- gheny and State of Pennsylvania, have invented ,a new and useful Improvement in Dvnamoslillectric Machines, of kwhich the following is a specifica-tion.

vMy invention relates to dynamo-electric machines, and it has special reference to the core and frame structures of fan motors and The object of my invention is to provide a simple and inexpensive field magnet' structure that shall require no machining and that shall embody air ducts for ventilation and a large outer surface for radiation and also comprise a minimum number of parts.

The field magnet members of small direct current motors are usually made of cast iron and lrequire considerable machine work before they are ready for assembling and their end brackets are also machined to some extent. y

According to my invention, lconstruct the main body portion ofthe eld magnet core and frame of a series of similar flat castings which are provided with registering projections and recesses to space them apart for ventilation, and with three points of contact which establish and maintain their relative positions. The castings also cooperate with the end brackets in such a manner that no machine work 'is required on any ipart of the eld magnet structure except such as.may benecessary to provide suitable shaft bearings in the end bells.

Figure l of the accompanying drawings is a partially sectionaLelevation of a ceiling fan motor having a ield magnet constructed in accordance with my invention. Fig. 2 is a detail view of one of the parts of the structure shown in Fig. l, and Figs. 3, 4 and 5 are, respectively, sectional views on lines III-III, IV-IV and V--V of Fig. 2. Referring to theI drawings, the structure here shown comprises an armature or rotor 1, which is rotatable on a verticalaxis, and

a' fieldl member or stator 2 comprising end frames g3 and- 4 and a field magnet core structure 5 which is composed of a plurality of relatively thin castings 6. Each of the castings 6 is provided with a frusto-conical projection 7, a boss S and a trapezoidal projection 9 u'pon one side near its periphery.

|The castings are correspondingly recessed directly opposite the projections, so that, when they are assembled side by side, a projection of one castingv rests in a corresponding recess 'of the adjacent casting, as shown in Fig'l. The outer edges of the castings are preferably rounded in order to improve the appearanceof the device by rendering its irregularities inconspicuous. A larger heat radiating surface is also provided by this means.

The frusto-conical projection 7 of one plate and the corresponding recess of the next adjacent plate serve to fix one point of engagement between the two, irrespective of theirregularity 4of the castings. The

central plane of the trapezoidal projection 9, if extended, would bisect the frusto-conical projection, and the recess in which the former projection rests is soproportioned that the projection is readily seated without tending to pull the fru`sto-conical projection out of its seat, even if the two projections and recesses are not spaced accurately. Finally, the boss 8 rests against the face of the adjacent plate and establishes the third number and form of the polar projections constitute no part ofmy present invention, and may be varied as desired.

Since it is my desire and intention to avoid all machine work upon the eld mag- 'net frame and core structure, it is important that the castings 6 shall be so assembled that a uniform air gap shall bp1 provided' between the pole piece faces and t e motorl armature. The desired uniformity of air gap can be insured only by so assembling the castings that corresponding points thereof shall be in exact alinement parallel to the motor axis, and such alinement is secured by providing the respective castings with unlike projections and corre ndingrecesses.

The end frames 3 and copstitute bearing j housings for the shaft of the rotor 1, vin the usual manner, and each of them is provided with recesses 14, which correspond, in size -and location, to those on the castings which are assembled between them. The recesses 14, in the upper end frame 3, are engaged by the projections of the adjacent casting 6, and bolts 16 secure the assembled castings to this member, so that the lower end frame may be removed, as desired, to permit the inspection or removal of the rotor.

The bolts 16 extend loosely through holes 17 in the projections of "fthe castings and nuts are screwed upon their lower ends.

Two of the nuts are made to correspond in form to the frusto-conical projections of the castings and the third serves merely as a spacer between the end frameand the adjacent plate. `Nuts 18 are screwed upon the bolts 16 to hold the lower end frame 4 in position. Since the castings 6 are identical and are very simple in outline, they may be produced in large quantities and at a very slight expense.

fications maybe effected within the spirit `and scope of my invention.

l claim as my invention: l 1; In a dynamo-electric machlne, the combination with a rotor, of a field magnet ystructure comprising a plurality of similar cast plates of magnetizable material having cooperating projections and recessesl for spacing the plates apart and for maintaining a Xed relation between them, and end frames having, recesses corresponding to those of the plates and constituting bearing housings for the rotor shaft.

2. In a dynamo-electric machine, the combination with a rotatable armature and a ield magnet structure comprising a plurality of like cast iron plates having coperating projections and recesses and lugs for fixing their relative positions and for spacing them apart, of end frames or brackets recessed to correspond to the plates 4which are assembled between them.

3. In a vdvnamo-electric machine, the combination with a rotatable armature and a field magnet structure comprising a plurality vof like-cast iron plates having coperating projections and recesses and lugs for fixing their relative positions and for spacing them apart, of an end frame or bracket constituting a bearing for the rotatable armature and recessed to receive the projec tions of the adjacent plate, bolts extending through the end frame and through the plates, spacing nuts coperating with the bolts Vfor securing the assembled plates to the end frame, and a second end frame removably secured to the assembled field magnet structures..

In testimony whereof, I have hereunto subscribed my name this I17th dayl of Dec., 1909.

FRED R. KUNKEL.

. Witnesses:

N. M. WEBER, B. B. H1Nus.` 

